Effects of concentrate type and leveland forage type on chewing time of steers.

Abstract

Four double 3×3 latin square experiments were conducted to study the efforts of three concentrate-to-forage ratios (10:30, 40:60 and 70:90), three concentrate types and four forages, on chewing time of steers. Diets were fed for 14 days and chewing was monitored for the last 48 hours. Chewing time was reduced (P<.05) with each increase of concentrate level. Long hay and coarsely cut wheat silage resulted in more chewing time (P<.05) than finely cut sorghum or corn silage. Citrus pulp increased chewing time over ground corn or soybean mill feed. While there was some indication of interaction among forages and concentrate levels, mean values were linear, so we assumed the effect of concentrate and forage dry matter on chewing time was additive. Chewing time for the concentrate and forage was partitioned by regression. Roughage value index (chewing time per kilogram of dry matter) was 68.9 ± 3.2 SE for wheat silage, 67.3 ± 1.2 for corn silage, 59.7 ± 2.4 for sorghum silage, 78.5 ±5.5 for bermudagrass hay, 30.9 ± 15.4 for citrus pulp, 5.1 ± 4.2 for ground corn, and 8.4 ± 2.8 for soybean mill feed.